G'day Moosers,
I'm currently working on some quick lightning talks demonstrating Moose and
why it's useful. One of the examples I'm using for roles looks like this:
package SunSmart;
use Moose::Role;
use Weather::Google;
use constant HOT => 28; # Deg C.
requires 'go_outside';
requires 'location';
before 'go_outside' => sub {
my ($self) = @_;
my $weather = Weather::Google->new(
$self->location
);
if ($weather->current->{temp_c} > HOT) {
print "Don't forget your hat!\n";
}
}
In short, if something has a location, and the ability to go_outside, then
we can give it the SunSmart role, and it won't forget its hat if it's too hot.
Unfortunately for me, `location` is an attribute on practically all of my
classes, and Moose doesn't seem to like having an attribute to satisfy a
'requires':
'SunSmart' requires the method 'location' to be implemented by
'Person::Social'but the method is only an attribute accessor at
/usr/lib/perl5/site_perl/5.8/Moose/Meta/Role/Application.pm line 59
This makes me sad, since I really *do* require a location method, but it's
absolutely fine if it's an attribute.
I know there have been some discussions about this in the past, with the
possibility of a 'requires_attr' or similar keyword, although to the best of
my knowledge this is not yet implemented.
In the meantime, is there any easy[1] way to tell Moose that attributes are
just fine to satisify 'requires' dependencies?
Many thanks,
Paul
[1] Since I'm writing short talks for mixed audiences, I can't show anything
too scary. Sure, I'm willing to dig around in the guts of all sorts of
things, but I'm trying to dispel the myth that as a regular Perl programmer
you should have to.
--
Paul Fenwick <[email protected]> | http://perltraining.com.au/
Director of Training | Ph: +61 3 9354 6001
Perl Training Australia | Fax: +61 3 9354 2681
